Immune Systems

• Pathogen = any disease-causing organism
• Antigen = foreign substance that triggers an immune response
• Defence mechanisms, Non specific - Response is immediate and same for all pathogens eg. physical barrier (skin, mucus, nose hair), phagocytosis
• Defence mechanisms, specific - Response is slower and specific to each pathogen eg. Cell-mediated response (T lymphocytes), humoral response (B lymphocytes)
• Phagocytosis - the process of engulfing and digesting foreign particles
• Chemotaxis - the movement of cells to a chemical stimulus.
• Chemoattractant: a substance which attracts motile cells of a particular type
• T lymphocytes mature and grow in the thymus gland
• B lymphocytes mature and grow in bone marrow
• T + B lymphocytes move around the blood stream
• What cells are identified by a T cells?

  Antigens (Transplanted cells, Phagocytes, Cancer cells, A body cell)
• Humor = body fluids
• How do B cells make antibodies?

  Through a process called B cell activation and differentiation, B cells produce and release antibodies.
• Ig = Immunoglobulin
• What do antibodies do?

  Antibodies neutralises toxins, Antibodies can attach to virus prevents from entering a cell, Antibodies do an agglutination of pathogens
• Monoclonal antibodies are produced by cloning a single antibody gene
• HeLa cells are used in the production of vaccines, antibodies, and other medical products
• 3 Different things monoclonal antibodies are used for: Medical diagnosis, Pregnancy testing, Targeting specific cells (cancerous cells)
• ELISA test : Enzyme-linked immunosorbent assay
• Active immunity is when the body produces antibodies to a specific antigen
• Passive immunity is when the body is given antibodies from another person or animal
• Natural active immunity is when you are exposed to a pathogen and your body produces antibodies
• Artificial Active Immunity - Forms basis of vaccination (immunisation), involves inducing on immune system
• Features of a successful vaccination programme : 1. Vaccines are safe (few side effects) 2. Vaccines are effective 3. Vaccines are affordable (economically availability)